Raman spectra will be obtained for aqueous solutions of several bacteriophage and plant viruses (phi X174, T4, Tobacco Mosaic Virus, Cucumber Mosaic Virus). The Raman spectra of protein and RNA or DNA components of these viruses will be obtained where possible. Infrared spectra of D2O solutions will be measured for these viruses and their components on a selective basis. The data will be used to answer questions concerning the molecular structure of the viral components and the interactions which stabilize the viral structure (e.g. what fraction of the phosphodiester linkages are in an ordered configuration, what fraction of the amino-acid residues are in alpha-helical, beta-sheet and irregular conformations, are the adenine or cytosine residues protonated at lower pH, are S-H groups exposed to solvent, etc.). BIBLIOGRAPHIC REFERENCES: Studies of Virus Structure by Laser-Raman Spectroscopy II. MS2 Phage, MS2 Capsids and MS2 RNA in Aqueous Solutions, G. J. Thomas, Jr., B. Prescott, P. E. McDonald-Ordzie and K. A. Hartman, J. Mol. Biol. 102, 103 (1976). Studies of Virus Structure by Laser-Raman Spectroscopy III. Turnip Yellow Mosaic Virus, T. Turano, K. A. Hartman and G. J. Thomas, Jr., J. Phys. Chem. (May 20, 1976).